<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="#">
<label>
    <!--required是否为必填-->
    <span>自我介绍</span>
    <textarea name="info" rows="20" cols="100"
    required="required"
    autofocus="autofocus"
    placeholder="请在此输入你的个人信息"
    maxlength="500"
    ></textarea>
    <button>提交</button>
</label>
</form>
</body>
</html>